/****************************************************************************

 Copyright (C) 2002-2014 Gilles Debunne. All rights reserved.

 This file is part of the QGLViewer library version 2.8.0.

 http://www.libqglviewer.com - contact@libqglviewer.com

 This file may be used under the terms of the GNU General Public License 
 versions 2.0 or 3.0 as published by the Free Software Foundation and
 appearing in the LICENSE file included in the packaging of this file.
 In addition, as a special exception, Gilles Debunne gives you certain 
 additional rights, described in the file GPL_EXCEPTION in this package.

 libQGLViewer uses dual licensing. Commercial/proprietary software must
 purchase a libQGLViewer Commercial License.

 This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

*****************************************************************************/

#include "mouseGrabber.h"

#include <QGLViewer/manipulatedFrame.h>

using namespace qglviewer;
using namespace std;

void CameraPathPlayer::checkIfGrabsMouse(int x, int y, const Camera *const) {
  // Rectangular activation array - May have to be tune depending on your
  // default font size
  setGrabsMouse((x < 80) && (y < yPos()) && ((yPos() - y) < 16));
}

void Viewer::displayPlayers() {
  for (int i = 0; i < nbPlayers_; ++i) {
    CameraPathPlayer *cpp = player_[i];
    if (cpp) {
      QString s;
      if (cpp->grabsMouse()) {
        glColor3f(1, 1, 1);
        if (camera()->keyFrameInterpolator(i)->numberOfKeyFrames() > 1)
          s = "Play path F" + QString::number(i);
        else
          s = "Restore pos F" + QString::number(i);
      } else {
        glColor3f(0.6f, 0.6f, 0.6f);
        if (camera()->keyFrameInterpolator(i)->numberOfKeyFrames() > 1)
          s = "Path F" + QString::number(i);
        else
          s = "Pos F" + QString::number(i);
      }
      drawText(10, cpp->yPos() - 3, s);
    }
  }
}

void Viewer::updatePlayers() {
  for (int i = 0; i < nbPlayers_; ++i) {
    // Check if CameraPathPlayer is still valid
    if ((player_[i]) && (!camera()->keyFrameInterpolator(i))) {
      delete player_[i];
      player_[i] = NULL;
    }
    // Or add it if needed
    if ((camera()->keyFrameInterpolator(i)) && (!player_[i]))
      player_[i] = new CameraPathPlayer(i);
  }
}

void Viewer::init() {
  // Absolutely needed for MouseGrabber
  setMouseTracking(true);

  // In order to make the manipulatedFrame displacements clearer
  setAxisIsDrawn();

  // Initialize the CameraPathPlayer MouseGrabber array
  nbPlayers_ = 12;
  player_ = new CameraPathPlayer *[nbPlayers_];
  for (int i = 0; i < nbPlayers_; ++i)
    player_[i] = NULL;

  // Create a scene with several spirals.
  const int nbSpirals = 7;
  for (int i = -nbSpirals / 2; i <= nbSpirals / 2; ++i) {
    Spiral s;
    s.setPosition(Vec(1.8f * i / nbSpirals, 0.0, 0.0));
    spiral_.push_back(s);
  }

  restoreStateFromFile();

  help();
}

void Viewer::draw() {
  for (QList<Spiral>::const_iterator it = spiral_.begin(), end = spiral_.end();
       it != end; ++it)
    (*it).draw();

  updatePlayers();
  glDisable(GL_LIGHTING);
  displayPlayers();
  glEnable(GL_LIGHTING);
}

QString Viewer::helpString() const {
  QString text("<h2>M o u s e G r a b b e r </h2>");
  text += "This example illustrates the use of <i>MouseGrabber</i>, which is "
          "an abstract ";
  text += "class for objects that react (usually when the mouse hovers over "
          "them).<br><br>";
  text += "Define new camera paths (or positions) using "
          "<b>Alt</b>+[<b>F1</b>-<b>F12</b>]. ";
  text += "New <i>MouseGrabbers</i> are then created and displayed in the "
          "upper left corner. ";
  text += "Note how they react when the mouse hovers, and click them to play "
          "the associated path.<br><br>";
  text += "<i>ManipulatedFrame</i>, such as the ones which define the spirals' "
          "positions, are ";
  text += "also <i>MouseGrabbers</i>. When the mouse is close to the spiral "
          "center, the <i>ManipulatedFrame</i> ";
  text += "will grab to mouse click (as if the <b>Control</b> key was "
          "pressed). This is very convenient ";
  text += "to intuitively move scene objects (such as lights) without any key "
          "or GUI interaction.<br><br>";
  text += "Note that <code>setMouseTracking()</code> must be enabled to use "
          "<i>MouseGrabbers</i>.";
  return text;
}

void Spiral::draw() const {
  glPushMatrix();
  glMultMatrixd(mf_.matrix());

  // Draw a spiral
  const float nbSteps = 100.0;
  glBegin(GL_QUAD_STRIP);
  for (float i = 0; i < nbSteps; ++i) {
    float ratio = i / nbSteps;
    float angle = 21.0 * ratio;
    float c = cos(angle);
    float s = sin(angle);
    float r1 = 0.2 - 0.15 * ratio;
    float r2 = 0.16 - 0.15 * ratio;
    float alt = 0.2f * (ratio - 0.5);
    const float nor = .5;
    const float up = sqrt(1.0 - nor * nor);

    if (mf_.grabsMouse())
      glColor3f(1 - ratio, 0.8f, ratio / 2.0);
    else
      glColor3f(1 - ratio, 0.2f, ratio);

    glNormal3f(nor * c, up, nor * s);
    glVertex3f(r1 * c, alt, r1 * s);
    glVertex3f(r2 * c, alt + 0.01, r2 * s);
  }
  glEnd();

  glPopMatrix();
}
